There is little data about the intravascular ultrasound (IVUS) findings in the patients with vasospastic angina, especially with respect to patterns of vascular remodeling.

Coronary spasm was documented by angiography and ECG evidence of ischemia in 36 patients after administration of ergonovine (cumulative doses up to 350 microgram). After relief of spasm using 1,000 microgram of intracoronary nitroglycerin, IVUS imaging was performed and analyzed using standard methodology. The 36 focal spasm sites were compared to the proximal and distal reference segments.

The angiographic baseline minimum lumen diameter measured 1.78±0.66mm, which decreased to 0.66±0.38mm with ergonovine provocaton (p<0.0001), increased to 2.66±0.64mm after intracoronary nitroglycerin (p<0.0001 compared to baseline and post-ergonovine), and did not change after the IVUS imaging (2.66±0.63mm, p=.9). Coronary artery spasm was observed in angiographically normal segments in 6 patients and near normal segments (<10% angiographic diameter stenosis by visual estimate) in 30. Atherosclerotic lesions were observed at all coronary spasm sites; the mean plaque burden measured 56% at the spasm site and 35% at the reference site. The plaque composition of spasm site was hypoechoic in 31 and hyperechoic, noncalcific in 5; there was no calcium. Positive remodeling (spasm site arterial area>proximal reference) was present in 5; intermediate remodeling (proximal reference >spasm site >distal reference arterial area) was present in 7; and negative remodeling (spasm site arterial area<distal reference) was present in 24.

Sites of focal vasospasm in patients with vasospastic angina showed characteristics of early atherosclerosis except for an unusually high incidence of negative arterial remodeling.